The invention relates to a reaction tube assembly for automatic analyzers.
Before describing the invention, it will be appropriate to give a brief description of conventional arrangements with reference to FIGS. 1 to 3. Referring to these Figures, there is shown a conventional automatic analyzer 1 which is associated with a control system 2. On its front side, the analyzer 1 has a shelf 1a which centrally carries a sample disc 3 and also carries a pair of conventional reaction tube discs 4, 5 on the opposite sides thereof (see FIG. 2). The analyzer includes a top panel 1b inside which are housed storage and supply devices 19a, 19b for a dilution solution and a sample solution, respectively, as well as a colorimeter 21 (see FIG. 3) for examining the results of analysis. The analyzer also includes a bottom cabinet 1c within which are housed a thermostat 20 for heating the reaction tubes and drives associated with various parts of the analyzer.
The analyzer 1 is electrically connected with the control system 2 and is responsive to instructions from the latter for its operation. Information representing the analytical results in supplied to the control system 2. The control system 2 includes a control mechanism (not shown) which is designed to perform a programmed operation. On its front side, the system 2 includes a panel 2a on which various meters and dials are mounted, and also includes a recording device 6 which records the resulting analytical information.
Both the sample disc 3 and the reaction tube discs 4, 5 are adapted to rotate intermittently in the directions of arrows a, b and c, respectively, in a synchronous manner so that a plurality of sample vessels 7 (see FIG. 2) which are disposed along the periphery of the disc 3 can be aligned with a plurality of U-shaped reaction tubes 8, 9 which are also disposed along the periphery of the discs 4, 5. If desired, the discs 4, 5 may be driven so that a plurality of reaction tubes 8, 9 rather than a single one of them can be fed in one operation. A sample such as the one used in the clinical examination, chemical specimen, and specimen of animals, plants or minerals is contained in small quantities in the vessels 7, and can be transferred and distributed to the individual reaction tubes 8, 9 by means of two pairs of sample transfer arms 10, 11. It is to be noted that each pair of arms can transfer the sample to up to four reaction tubes in one operation.
The samples transferred and distributed among the reaction tubes 8, 9 move together with the discs 4, 5 while being subjected to an analytical treatment as shown in FIG. 3 so as to be converted into a solution to be examined, until it reaches the position of a pair of suction pipe support arms 12, 13 (see FIG. 2), respectively. At this position, the solution to be examined which is contained in the individual reaction tube 8 or 9 is drawn into the colorimeter 21 (see FIG. 3), which yields analytical information. The control system 2 is designed to control such operation of the analyzer 1 and to record the derived analytical information in a sequential manner.
Considering the operation of the arrangement somewhat more closely, the transfer of the sample from the vessels 7 to corresponding reaction tubes 8, 9 takes place through the movement of the distal end of sample suction and displacement pipes 10a, 10b, 11a, 11b of the arm pairs 10, 11 and through the operation of a pump unit P.sub.1 (see FIG. 3). As the pump unit P.sub.1 operates, a diluting solution is supplied to the sample from a diluting solution storage and supply device 19a, diluting the sample by a given factor. Referring to FIG. 3, it will be noted that one end of the reaction tubes 8, 9 has an opening of an increased size, thus forming reaction chambers 8a, 9a. The sample is introduced into these reaction chambers and is agitated by the supply of air delivered through the air supply port 8b, 9b which are formed at the other end of the reaction tubes. All of the reaction tubes 8, 9 are immersed in respective thermostat vessels 20 associated with the discs 4, 5, and are suitably heated or maintained at a desired temperature by the temperature control of the thermostat. It will be noted that when the air is supplied, the sample is driven upward into the reaction chambers 8a, 9a and is agitated by the air bubbles, but that when the supply of the air is interrupted, the sample moves down into the bottom of the U-shaped tube, permitting a satisfactory heating by the thermostat vessels. The air supply and its interruption are achieved by providing a pair of cover plates 14, 15 (see FIG. 2) which are located above the discs 4, 5 so as to be movable in the vertical direction or in a direction perpendicular to the plane of the drawing. The cover plates 14, 15 move down to close the ports 8b, 9b only permitting insertion of their individual pipes, and move upward to open the ports. A pair of retaining member 16a, 16b (see FIG. 2) are detachably mounted on the cover plates 14, 15 for positioning the air supply pipe or a reagent supply pipe with respect to the reaction tubes 8, 9.
A suitable quantity of reagent is supplied, at a suitable timing, from the reagent storage and supply device 19b to a reaction tube or tubes by using a pump unit P.sub.2 and a pipe (not shown) which is carried by the retaining member 16b. When the sample is supplied with a reagent, it is again subjected to agitation by the air supply and is further heated. The sample treated in this manner provides a solution to be examined, and when it reaches the position of the arm 12 or 13, a suction pump (not shown) draws the solution into a flow cell (see FIG. 3) of the colorimeter 21 for its analytical determination. The latter comprises a lamp 21a, an interference filter 21b, a prism 21c and a detector 21d. The results of analysis are recorded by the recorder 6, and the used solution which has been examined is taken out of the apparatus in a suitable manner. The emptied reaction tubes 8, 9 are cleaned with rinsing water supplied through rinsing water tubes 17, 18 (see FIG. 2) so as to be prepared for the next analyzing cycle.
It will be noted that in the conventional automatic analyzer, the solution to be examined which is contained in a reaction tube must be conveyed to the colorimeter, requiring a transfer apparatus and a cleaning apparatus for the flow cell. This resulted in the complication and the increased size of the general arrangement, and required a troublesome treatment.